Female Bladder Outlet Obstruction (BOO)


Bladder outlet obstruction (BOO) in women is rarely diagnosed but many urologists now appreciate that this is an under-diagnosed condition and with increased awareness of it, the condition is being diagnosed and treated successfully by specialists.


What symptoms will I have?

If you have symptoms of slow or poor urinary flow, having to push to pass urine, inability to empty your bladder completely, having to pass urine frequently or recurrent urinary tract infections, you could have BOO (although other bladder conditions can cause similar symptoms). In some situations, you may not be able to pass urine at all – this is called urinary retention.


You will need to have an examination of your abdomen and your vagina/pelvis, you will always be offered a chaperone for this.


What tests will I need to have?

If we suspect you have BOO from your symptoms and examination, we may ask for any of the following tests:

A urine sample which we will check for an infection
A pelvic ultrasound scan to check if any of the pelvic organs are compressing on your bladder to cause similar symptoms
A kidney ultrasound scan may be requested if you are experiencing frequent urinary tract infections
A flow rate test: you will be asked to drink until you have a comfortably full bladder and then pass urine into a specially designed toilet which measures how much urine you have passed and how fast you have passed urine. Your bladder will be scanned afterwards to see if you have emptied your bladder completely.


If the tests above lead us to suspect you have BOO, we may ask you to have a videourodynamic study and cystoscopy to finalise the diagnosis.


What are the causes of BOO in women?


Some of the causes of BOO in women are summarised in the table below:


Compression of the bladder or urethra (waterpipe)

Prolapse of pelvic organs

Large uterine masses e.g. fibroid

Following surgery on the bladder or urethra


Blockage of the urethra (waterpipe)

Stricture (narrowing) of the urethra

Meatal stenosis (narrowing of the opening of the urethra)

Urethral caruncle

Urethral diverticulum or cyst (a pocket forms alongside the urethra which may or may not be connected to the urethra and causes compression of it)


Problems with the sphincter within the urethra

The sphincter is a band of muscle within the urethra which maintains continence. The sphincter needs to relax fully to allow the passage of urine. Sometimes, the sphincter is unable to relax fully or at all.


Problems with relaxation of the

pelvic floor

Sometimes during childhood or adolescence, young girls can learn to tighten rather than relax their pelvic floor when passing urine. This leads to the symptoms described above and if left untreated can cause problems with the bladder and kidneys.



How will I be treated?


The treatment you are offered will vary according to which of the diagnoses above have caused your symptoms. If you are offered any of these options, you must discuss them fully with your Urologist before you agree to proceed.

Some of the treatments include:-


Pelvic floor physiotherapy

Intermittent self catheterisation liink

Urethral dilation link


Surgical removal of urethral diverticulum/cyst link

Sacral neuromodulation link

Suprapubic catheter insertion link

Formation of mitrofanoff link

or urinary diversion in extreme cases. link